The invention relates to a vibration damper for a shaft of a drive train, which shaft comprises a first shaft part and a second shaft part and an elastically deformable damping part, which is disposed between the shaft parts and which is acted upon by each of the two shaft parts in a rotationally locked manner, the first shaft part comprising a sleeve comprising radially inwardly oriented rotary drivers for the damping part, the second shaft part comprising an inner part comprising radially outwardly oriented rotary drivers for the damping part, the sleeve and the inner part being constructed and mated to each other in such a way that an end region of the inner part is surrounded by the sleeve, the damping part being disposed radially between the sleeve and the inner part with the damping part surrounding the end region of the inner part, and the damping part comprising negative profiles, with which the rotary drivers engage.
Special vibration dampers are known as so-called Hardy disks or flexible disks in the prior art. German utility model no. DE 93 13 417 U1 shows a corresponding structure thereof. Here, two radially expanded flange parts that are each disposed on a shaft part or another part transferring the rotation of the shaft are connected in an alternating manner over the circumference to an elastic disk made, for example, of rubber/steel or nylon meshwork. The elastic disk serves as a torsional vibration damper for absorbing torsional shocks or vibrations and for compensating a small angular or axial offset between the components associated with the flange parts. In order to be able to transmit the required torque by means of such a damping device, the diameter of the elastic disk must be dimensioned appropriately as a result of the circumferential loads acting upon the elastic disk so that a diameter that is many times that of the shaft must be provided for the damping unit and allowed for in the corresponding installation space. The high surface pressure at the transition points between the flange parts and the elastic disk and the resulting flexing leads to an undesirable heat development and high demands on the stability of the elastic disk.
An active vibration damping of drive shafts is described in EP 1,146,248 (=DE601 28 851). Here, a suitable counter-oscillator is activated in dependence on the measurements of a shaft speed sensor made of a composite material having piezo-electric properties. This construction is very elaborate and cost-intensive.
In the case of jaw clutches, it is known to provide elastic shaped parts between the interlocking jaws [e.g., GB 1,528,465 (=DE 25 42 948) or DE 298 06 632 U1].
Published German patent application no. DE 197 55 307 A1 describes a drive shaft comprising an elastic support that has varying degrees of rigidity in directions extending perpendicularly to each other.
Furthermore, a coupling device comprising two coupling elements is known from U.S. Pat. No. 7,670,228 (=DE 10 2007 025 953) in which one coupling element comprises a tubular circumferential wall into which the arms of the other coupling element extend and which surrounds a damping part.
FR 1,128,208 discloses a likewise solid damping part that is mounted between two shaft sections disposed inside each other, in part.
Thus damping parts for vibration damping are mounted between shaft sections in the prior art, the damping part optionally encompassing a region of a first shaft section, and the second shaft section surrounding the damping part and the region of the first shaft section. The disadvantage of this known arrangement is that the damping characteristics of the solid and homogenously constructed damping parts are solely determined by the properties of the material used for the damping part. Therefore, the damping effect can be specified or adjusted only to a limited extent.